US1979162A - Starting mechanism - Google Patents

Description

Oct. 30, 1934. R, P. LANslNG 1,979,162

STARTING MECHANI SM Filed May 20. 1932 2 Sheets-Sheet l T- d.' f

*n i l l l l i Q t i BY g, Wa AMEX 0.6L 30, 1934.V R. P LANslNG 1,979,162

STARTING MECHANISM Filed May 20. 1952 2 Sheets-Sheet 2 INVENTOR. Fay/mma F Lans/'0? BY Patented Oct. 30, 1934 UNITED STATES STARTING MECHANISM Raymond P. Lansing, Montclair, N. J., assignor, by mesne assignments, to Eclipse Aviation Corporation, East Orange, N. J., a corporation of New Jersey Application May 20, 1932, Serial No. 612,624

11 Claims.

This invention relates to starting mechanism for internal combustion engines, and more particularly to starters of the electric type.

One of the objects of the present invention is to provide novel means for mounting a starter on the crankcase of an engine.

Another object is to provide novel means for mounting a starter, said means being so constructed as to absorb the shock either at engagement or backfire, or at any moment of overload between the starter and the engine.

I Still another object is to provide a novel mounting for starting mechanism which is so constructed that the complete starter assembly is adapted for yielding movement both axially and angularly with respect to the engine crankcase.

A further object is to provide an engine starter embodying novel means for holding the cooperating elements of the torque multiplying gear train in assembled relation. For claims to the combination including this novel holding means, or to the holding means per se, reference is to be had of my divisional application No. '113,047 filed February 26, 1934.

In transmitting torque from a source to a stationary member, a strain is placed upon the parts of the latter at the moment it is started and at moments when a sudden change in load occurs. These strains endanger the life of such stationary member as well as the operation of the en- Vtire plant. It is, therefore, a further object of Y starter which is rugged in construction, inexpensive to manufacture, and particularly adapted for use with small aviation engines.

The above and further objects and novel features of this invention will more fully appear from the following detailed description when taken in connection `with the accompanying drawings wherein one embodiment of the invention is illustrated. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not designed as a definition yof the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings wherein similar reference characters refer to similar parts throughout the several views:

Fig. 1 is a side elevation view, partly in section, of an engine starting device constructed according to the present invention; and

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1.

The illustrated embodiment of the present invention shows, by way of example, an engine starter yieldingly mounted on the crankcase 4 of an internal combustion engine, said starter comprising driving means such as an electric motor 5 adapted to rotatably drive a starter jaw clutch member 6 through suitable gearing to be hereinafter described in detail. The starter jaw 6 is adapted to be moved axially into and out of engagement with a complementary jaw 8 mounted on the crankshaft 9, or an extension thereof, of an engine, whereby said crankshaft may be rotatably driven and the engine started.

The starting unit as shown is provided with suitable housing means comprising a main housing member 10 adapted to be removably secured in a novel manner to the crankcase 4 and a motor housing 11 rigidly attached to the outer face of said main housing member by means of a plurality of elongated bolts, one of which is shown at 12. The extended portion of shaft 13 of motor 5 is rotatably supported in a suitable bearing 14 which is in turn mounted in the central hub portion of a transversely disposed wall or spider 15 that may be securely held in engagement with the inner end of housing 11 by means of bolts 12.

Suitable torque multiplying means, including a simple and eflicient reduction gear train, has been provided to transmit the power of motor shaft 13 to a driven member at a reduced speed with increased torque. The gear train, as shown, comprises a compound planetary gear member or pinion 16 having two sets of teeth 17 and 18 cut thereon, the diameter and number of teeth of one set being somewhat less than those of the other set, and said member being rotatably mounted as by means of bearings 19 on a shaft 20 rigidly Vsupported in a novel manner between two discs or rings 2l and 22 secured by means such as bolts 23 for rotation as a unit about the axis of shaft 13. Rings 21 and 22 are rotatably mounted on shaft 13 by means of bearings 24, the entire unit being retained onA shaft 13 by a nut 25 on the reduced end portion of said shaft. If desired, three gear members 16'may be employed, spaced 120 degrees apart and mounted in the manner shown in Fig. 1. Preferably the bolts 23 are of the same number, and spaced to alternate with the shafts 'Ihe larger portion 17 of member 16 is in constant mesh on one side with a pinion 26 suitably splined or keyed to shaft 13, and on its other side with a stationary internally toothed annular gear 27 secured between spider 15 and housing 10 by bolts 12. The smaller portion 18 of member 16 is in -constant mesh with gear teeth cut on the inner periphery of a bell shaped member 28 formed integrally with an inwardly extending hub portion 29 which is rotatably mounted in housing member 10 by means of suitable bearings 30 and 31. Appropriate means for maintaining these bearings in proper position may include a ring 32, a spacer 33, and 'a nut 34 threaded to the inner end of hub 29.

Suitable means are provided for drivably connecting gear member 28 to the starter jaw 6 in such a manner that the jaw may be moved into and out of mesh with the engine jaw 8. Preferably, such means is constituted by a jaw clutch assembly consisting, as shown, of a shaft 35 threaded into the hub portion 29 of gear member 28 and provided with longitudinal splines at its outer end to receive the interiorly splined tubular portion of starter jaw 6. Secured to the inner end of shaft 35 is a stop nut 36 for limiting the outward movement of said shaft with respect to.

hub 29. Relative axial movement between starter jaw 6 and shaft 35 is limited by rod 37 extending through central openings in each of these members. Preferably, a spring 38 surrounds the engine end of rod 37 bearing at one end against the inner face of starter jaw 6 and at its other end against the threaded shaft 35, the latter being provided with a recess into which a portion of spring 38 extends. The starter jaw 6 may be maintained on rod 37 by means of a nut 39 threaded thereon.

Preferably, automatic means are provided for insuring the meshing of the starter jaw 6 with complementary jaw 8 associated with the engine crankshaft 9. As shown, such means include a light metal housing 40 which is rigidly held in place by means of an annular shelf 41 on a member 47,further to be described. In the particular structure' illustrated, three arcuate members 42 surround the starter jaw 6 and are rotatably supported in an annular semi-circular channel 43 formed by outwardly bending the inner edge of housing member 40, each arcuate member having a bead which rests in said channel. A toroidal spring 44 received by grooves in the outer periphery of members 42 is provided for exerting an inward pressure on said members, thereby maintaining them in friotional engagement with housing 40. Each of the members 42 is provided with a suitable lug or projection 45 which extends inwardly into corresponding axial slots 46 in the outer periphery of starter jaw 6, thereby permitting vrelative axial movement between said jaw4 and members 42. Upon energization of the motor, rotation of starter jaw 6 is retarded by members 42 which slide in channel 43, whereupon the starter jaw moves inwardly into mesh with the jaw 8 by virtue of the coaction of the screw threads lon shaft 35 and hub 29. Preferably, the jaws 6 and Y 8 are provided with inclined teeth so that there will be an immediate disengagement of the starter jaw when its speed of rotationis exceeded by the engine jaw 8, that is, when the engine commences ring.

Novel means are provided for yieldingly mounting the above-described starting unit, or similar apparatus. on the crankcase vof an engine, in a manner such that the entire unit is adapted for movement in its pilot bearings relative to the crankcase, whereby any shock produced by a sharply changing torque or load is absorbed by suitable yielding means, thus preventing injury to and strain upon the mechanism. In the preferred embodiment shown, the housing 10 is provided at its inner face with an annular flange 47 which has cut therein a plurality of arcuate pilot slots 48v concentric with the axis of rotation of the starter mechanism and through which slidably extend supporting or pilot members such as stud bolts 49 threadedly received by the crankcase 4. Surrounding the outer portions of bolts 49 are coil springs 50 interposed between the outer face of flange 47 and adjusting nuts 51 threaded onto the outer ends of said bolts. IIt is thus seen that the starter is held firmly against the crankcase by the pressure of springs, 50 but is at the same time capable of both rotary and axial movement relative thereto. v

Means are provided for yieldingly resisting this rotary movement in either direction, and in the illustrated form the flange 47 is provided with laterally-extending ears 52 (preferably two, diametrically disposed) having openings 53 near their outer ends, the central axes of which are substantially perpendicular to the axis of rotation of the starter unit. Extending through the openings 53 are bolts 54 which are supported at their ends in any suitable manner such as by brackets 55 integral with or rigidly attached to the engine crankcase 4. Normally theears 52 are centrally positioned on the bolts 54, as shown in Fig. 2, and coil springs 56 surrounding said bolts on each side of said ears and abutting against brackets 55 serve to resist the rotational movement of the starter unit. For assisting in the support and proper seating of the latter, the annular shelf or abutment 41 aforementioned, has an outer face beveled at an angle permitting it to rock on the beveled annular opening 57 in the crankcase 4.

In operation, the motor 5 is energized from a suitable source of electrical energy (not shown) whereupon the shaft 13 rotates with the motor armature, and its motion is in turn transmitted through pinion 26, planetary gears 1'7, 18 and internal gear 28 to the hub 29. During the initial rotation of the hub 29, starter jaw 6 and shaft 35 are retarded by virtue of the frictional relation between arcuate members 42 vand housingy member 40, thereby causing relative rotation between hub 29 and shaft 35, whereupon the screw threads of said two last-named members coact and cause shaft 35 to move to the left in Fig. 1 carrying starter jaw 6 into mesh with engine jaw 8. It will be noted that the speed of rotation of the starter jaw at the instant of meshing is comparatively slight, thereby preventing a clashing of the jaw teeth. As soon as the said jaws have been brought into engagement', thereby establishing a positive driving connection between the starter and the engine, the members 42 commence rotating with the starter jaw 6 and continue to do so during the cranking operation. As soon as the engine fires and the speed of engine jaw 8 exceeds that of the starter jaw 6, the latter is moved to the right in Fig. 1 by virtue of the inclined teeth. l

As pointed out above, the inertia ofthe movable engine parts of the engine places a large sudden load upon the starter at the instant jaw 6 is engaged with jaw 8. As this sudden load is placed upon the starter, certain of the springs 56 yield and allow the engine starting unit to rotate bodilyv by reason of the pilot slots 48, thus preventing any sudden shock or strain upon the starter gearing and the motor. As soon as the inertia of the engine parts has been overcome and the starter has been brought up to normal speed, the tension in the springs 56 is thereby relieved and they return the starter to a neutral position such as shown in Fig. 2. In like manner, these springs, aided by the resilient members 50, will absorb any shock occasioned on the backfire of an engine and all variations in the load which may be placed on the driving unit.

There has thus been provided a novel engine starting mechanism which includes a simple and eicient compound epicyclic gear train and which is well adapted for practical use, which may be easily and cheaply constructed and assembled from rugged parts, thus reducing the possibility of failure of such parts and facilitating overhaul.

Novel means have also been provided in combination with said starter for yieldingly mounting the same on the crankcaseA of an engine to be started thereby eliminating the necessity of means integral with the starter assembly for protecting the parts thereof against sudden shocks and excessive or changing loads. By the provision of a yielding mount of this character, it is seen that the starter construction may be considerably simplified, its Weight materially reduced, and the need for friction means to protect the gearing is eliminated.

While there has been shown and described only one vform of the invention, it is to be expressly understood that the same is not limited thereto but may be embodied in various other mechanical forms. For example, it is to be understood that various other means may be provided for driving the starter and any suitable means for meshing the ja'ws may be provided in lieu of the means illustrated. It is also to be expressly understood that the mechanical details of the yielding mount illustrated may be altered and that the same is not in any sense limited to its use with engine starting apparatus, since the same may be employed with an engine-driving generator, or the like. Various other changes may also be made without departing from the spirit thereof. Reference will be had to the appended claims for a definition of the limits of the invention.

What is claimedis:

1. In combination with an* engine starter, means for mounting said starter on an engine crankcase, whereby said starter is adapted for limited rotary and axial movementrelative to said crankcase, means for yieldingly resisting said relative rotary movement, and additional means disposed at right angles to said last named means for-yieldingly resisting said relative axial movement.

2. In an engine starter of the type having a mounting extension disposed at one end thereof, means engageable with said mounting extension l' for mounting said starter on the crankcase of an engine whereby said starter shall be capable of limited rotary movement relative to said crankcase, and resilient means coiled about an axis transverse to the axis of rotation of the starter for resisting said relative rotation.

3. An engine starter of the type having a mounting extension disposed at one end thereof, means engageable with said mounting extension for mounting said starter on the crankcase of an engine whereby the starter shall be capable of limited rotary movement relative to said crankcase, and resilient means for resisting said relative rotation, said latter-named means including springs interposed between said starter and said crankcase.

4. In a power transmitting unit, a casing therefor, means for movably mounting said casing on a stationary member, resilient means for resisting the rotation of said casing relative to said member, and additional resilient means mounted transversely of said rst named resilient means for resisting relative axial movement of said casing and member.

5. In combination, a casing adapted to house a power unit, means for movably mounting said casing on a stationary member comprising a flange on said casing, said flange having arcuate slots therein, supporting members adapted for relative movement in said slots, a plurality of laterally extending ears on said flange, a plurality of brackets on said stationary member, and yielding means interposed between said ears and brackets for yieldingly resisting the motion of said casing relative to said stationary member.

6. In apparatus of the class described, the combination with an engine crankcase of a casing having a ilange provided with arcuate slots and a plurality of apertured ears, supporting rods secured to said crank-case and slidably extending through said slots, brackets on said crank-case, and yielding means associated with said ears and brackets for resisting angular movement of the casing relative to said crank-case.

'1. In apparatus of the class described, the combination with a supporting member of a casing, supporting rods secured to said member, means for mounting said casing on said rods whereby the former may have relative angular movement with respect to said member, and resilient means for yieldingly resisting said angular movement.

v8. In apparatus of the class described, the combination with an engine crankcase of a casing having a flange provided with arcuate slots and a plurality of apertured ears, supporting rods secured to said crankcase and extending through said slots, resilient means on said rods for resisting axial movement of said casing relative to said crankcase, brackets on said crankcase, rods extending through the apertures in said ears and supported by said brackets, and yielding means associated with said ears and brackets for resisting angular movement of the casing relative to said crankcase.

9. In apparatus of the class described., the combmation with a supporting member of a casing, supporting rods secured to said member, means for mounting said casing on said rods, whereby the former may have relative angular movement with respect to said member, resilient means for yieldingly resisting said angular movement, and resilient means on said rods for resisting axial movement of said casing relative to said member.

1G. In an engine starter, means for mounting said starter on the engine crank-case comprising a beveled part extending into the apertured portion of the crank-case, and having a rocking t therein to enable said starter to rock through an angle corresponding to the degree of bevel, and resilient means for yieldably resisting such rocking movement. 11. In an engine starter, means for mounting said starter on the engine crank-case comprising a part extending into the apertured portion of the crank-case, and having a rocking t th-ere-

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